1,344 research outputs found

    XMM-Newton and NICER Measurement of the Rms Spectrum of the Millihertz Quasiperiodic Oscillations in the Neutron-star Low-mass X-Ray Binary 4U 1636–53

    Get PDF
    We used two XMM-Newton and six Neutron Star Interior Composition Explorer observations to investigate the fractional rms amplitude of the millihertz quasiperiodic oscillations (mHz QPOs) in the neutron-star low-mass X-ray binary 4U 1636?53. We studied, for the first time, the fractional rms amplitude of the mHz QPOs versus energy in 4U 1636?53 down to 0.2 keV. We find that, as the energy increases from ∼0.2 to ∼3 keV, the rms amplitude of the mHz QPOs increases, different from the decreasing trend that has been previously observed above 3 keV. This finding has not yet been predicted by any current theoretical model; however, it provides an important observational feature to speculate whether a newly discovered mHz oscillation originates from the marginally stable nuclear burning process on the neutron-star surface.Fil: Lyu, Ming. Xiangtan University; ChinaFil: Zhang, Guobao. Chinese Academy Of Sciences; ChinaFil: Méndez, Mariano. University Of Groningen, Kapteyn Astronomical Institute; AlemaniaFil: Altamirano, D.. University of Southampton; Reino UnidoFil: Mancuso, Giulio Cesare. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Argentino de Radioastronomía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Argentino de Radioastronomía; ArgentinaFil: Xiang, Fu-Yuan. Xiangtan University; ChinaFil: Xiao, Huaping. Xiangtan University; Chin

    Heart–brain interaction in cardiogenic dementia: pathophysiology and therapeutic potential

    Get PDF
    Diagnosis and treatment of patients with cardiovascular and neurologic diseases primarily focus on the heart and brain, respectively. An increasing number of preclinical and clinical studies have confirmed a causal relationship between heart and brain diseases. Cardiogenic dementia is a cognitive impairment caused by heart dysfunction and has received increasing research attention. The prevention and treatment of cardiogenic dementia are essential to improve the quality of life, particularly in the elderly and aging population. This study describes the changes in cognitive function associated with coronary artery disease, myocardial infarction, heart failure, atrial fibrillation and heart valve disease. An updated understanding of the two known pathogenic mechanisms of cardiogenic dementia is presented and discussed. One is a cascade of events caused by cerebral hypoperfusion due to long-term reduction of cardiac output after heart disease, and the other is cognitive impairment regardless of the changes in cerebral blood flow after cardiac injury. Furthermore, potential medications for the prevention and treatment of cardiogenic dementia are reviewed, with particular attention to multicomponent herbal medicines

    Assessing Nurses' Workplace Social Capital : A Study Protocol for Culturally Appropriate Instrument Development

    Get PDF
    Workplace social capital positively influences the quality but reduces the cost of healthcare services. Academic research suffers from limited and inadequate culturally sensitive nurses' workplace social capital instruments. Here we report on the design and protocol of a culturally focused instrument development study in China. The overarching objective of our dual phase study is to develop and validate a questionnaire measuring nurses' workplace social capital tailored toward Chinese cultural values and norms. In the first phase of INSTRUMENT DEVELOPMENT, the qualitative phase, we will conduct interviews with purposefully sampled nurses from five geographically diverse regions capturing 16 provinces in China to formulate the initial version of the Nurses' Workplace Social Capital Questionnaire (NWSCQ). Data collection will be stopped at the saturation point and content analysis will be performed for interview data in parallel. The initial version of the NWSCQ will be evaluated and confirmed by two-rounds of expert consultation (target N = 20) and pre-tested among 70 nurses. During the second phase of INSTRUMENT VALIDATION or the quantitative phase, we will validate the psychometric properties of the NWSCQ. The validity and reliability of the questionnaire will be examined and validated through three cross-sectional surveys among nurses (target N = 1154) randomly selected from 12 tertiary hospitals. We have reported our study protocol with the intention of sharing our experience with researchers in other countries who are striving to advance the phenomenon of culturally sensitive and social normatively appropriate nurses' workplace social capital. Findings from our study should advance the development of culturally appropriate and valid instrument of nurses' workplace social capital, another important step toward recognition and incorporation of cultural diversity in the daily operation of healthcare industry.Peer reviewe

    Global genetic diversity, introgression, and evolutionary adaptation of indicine cattle revealed by whole genome sequencing

    Get PDF
    Indicine cattle, also referred to as zebu (Bos taurus indicus), play a central role in pastoral communities across a wide range of agro-ecosystems, from extremely hot semiarid regions to hot humid tropical regions. However, their adaptive genetic changes following their dispersal into East Asia from the Indian subcontinent have remained poorly documented. Here, we characterize their global genetic diversity using high-quality whole-genome sequencing data from 354 indicine cattle of 57 breeds/populations, including major indicine phylogeographic groups worldwide. We reveal their probable migration into East Asia was along a coastal route rather than inland routes and we detected introgression from other bovine species. Genomic regions carrying morphology-, immune-, and heat-tolerance-related genes underwent divergent selection according to Asian agro-ecologies. We identify distinct sets of loci that contain promising candidate variants for adaptation to hot semi-arid and hot humid tropical ecosystems. Our results indicate that the rapid and successful adaptation of East Asian indicine cattle to hot humid environments was promoted by localized introgression from banteng and/or gaur. Our findings provide insights into the history and environmental adaptation of indicine cattle

    Large expert-curated database for benchmarking document similarity detection in biomedical literature search

    Get PDF
    Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe
    corecore